Field
This disclosure relates generally to semiconductor structures, and more specifically, to through substrate vias (TSV) and methods of forming the same.
Related Art
Semiconductor devices are often found in a large spectrum of electronic products—from sewing machines to washing machines, from automobiles to cellular telephones, and so on. These semiconductor devices are typically mounted on a substrate such as a printed circuit board. In order to keep product costs low or to reduce product costs, it is common to minimize the amount of material used within the product, frequently reducing the size of the product itself. As electronic products are reduced in size, printed circuit board real estate becomes more precious putting additional constraints on the size, number, and features of semiconductor devices—pin count, higher integration, package-on-package arrangements, and so on.
Through substrate vias (TSV) provide an alternative to wire bonds and flip chips, allowing semiconductor devices to be formed by vertically stacking two or more semiconductor chips. A TSV is a vertical electrical interconnect that passes through a device wafer or other semiconductor substrate and facilitates electrical connections between two or more vertically stacked wafers and/or chips. However, TSV fabrication is impacted by associated process constraints, complexity, and resulting yield.